Lead plaintiffs Leo and Jessica Ramirez took on the West Palm Beach, Fla.-based lender in Feb. 14 complaint filed in Atlanta. A representative at Ocwen’s call center was unable to provide comment.

Under regulations by the Federal Housing Administration, the complaint says, lenders can charge post-payment interest only if the borrower makes the full payment after the first of the month, and even then only if the lender has provided the borrower with the FHA disclosure form.

The FHA disclosure form explains borrowers’ rights, including the terms under which a lender can collect post-payment interest and directions about how borrowers can avoid this penalty. This form is required, according to the complaint, because it alerts borrowers at the time of payment to the fact that the Housing Urban Development Handbook states the lender is asserting the right to collect the payment.

“All of the relevant government agencies now agree that collecting postpayment interest is an unfair prepayment penalty and is against public policy,” the complaint states.

Tuesday’s class action accuses Ocwen Loan Services of reaping hundreds of millions of dollars in illegal interest from countless borrowers in this fashion. In each case, the class claims, Ocwen failed to provide consumers with the FHA disclosure form and instead gave them one that used its own unauthorized language that does not explain to borrowers how to avoid this penalty.

The lead plaintiffs say this is what happened to them. “Because Ocwen required Leo and Jessica Ramirez to pay interest for the entire month of March and April – even though the Ramirezes paid the full unpaid principal on April 4, 2013, Ocwen collected post-payment interest,” the complaint states.

Seeking punitive damages and an injunction, the class alleges breach of contract. They are represented by Archie Grubb II of Beasley, Allen, Crow, Methvin, Portis & Miles of Montgomery, Alabama.